Irritable bowel syndrome (IBS) is a heterogeneous gastrointestinal (GI) disorder characterized by frequent and debilitating symptoms (e.g., diarrhea, bloating, abdominal pain, urgency to defecate, gas, and fecal incontinence), often with cyclical waxing and waning of symptoms. IBS causes substantial impairment in health-related quality of life (QOL), loss of work and productivity, social embarrassment, and high health care costs. The prevalence of IBS is believed to be 10 to 15% of the United States (US) population; however, only 15% of IBS patients actually seek medical treatment, which may be due in part to the lack of effective therapies. Despite the tremendous burden of IBS, on patients and the healthcare system, there remains a significant unmet need for effective and safe therapies, particularly for IBS with diarrhea (IBS-D).
The exact cause of IBS is unknown, but several hypotheses have been proposed. One prevalent hypothesis implicating enteric bacterial dysbiosis suggests that IBS symptoms are caused by alterations and abnormal colonization of the gut microbiome, which is also involved in normal physiological function. Enteric bacterial dysbiosis is best viewed as an altered microbial ecosystem and not an infection per se.
There is a need in the art to diagnosis those in need of treatment for IBS. There is also a need in the art to provide a prognostic indicator of those about to be treated or those that are being or have been treated for IBS.
There is also a need in the art for a method of providing symptomatic relief for subjects with IBS-D following a short treatment course along with a low risk of adversely contributing to concerns with multi-drug antibiotic resistance.